1.7.2.3 additional information enzyme is probably required for acquisition of molybdenum cofactor and translocation of the trimethylamine reductase TorA, EC 1.6.6.9, monomeric and dimeric enzyme forms bind to Tor A, the dimeric form binds more efficiently 1.7.2.3 additional information regulator TorR and sensor TorS, encoded by genes torR and torS in the same operon as torA, are required for the trimethylamine oxide respiration pathway 1.7.2.3 additional information the enzyme binds to the trimethylamine oxide reductase TorA apoenzyme, EC 1.6.6.9, recognizing a signal peptide, and allows TorA to bind the essential molybdenum cofactor for transport from the periplasm across the cytoplasmic membrane, TorD is not involved in the transport itself, TorD has a regulatory and controlling function on TorA assembly 1.7.2.3 additional information TorD chaperone is a chaperone of trimethylamine oxide reductase, EC 1.6.6.9, addition of the chaperone activates the TorA apoenzyme up to 4fold, allowing its maturation, in absence or presence of the TorA molybdenum cofactor, TorD modifies the TorA apoenzyme conformation in absence of the cofactor, probably making the apoenzyme competent for cofactor binding, binding study 1.7.2.3 additional information TorD is an essentially required chaperone for cofactor binding and enzyme maturation of the trimethylamine oxide reductase TorA, EC 1.6.6.9, in absence of TorD at 42°C, the TorA is poorly maturated and almost completely degraded, at elevated temperatures above 37°C TorD prevents the missfolding of TorA apoenzyme before molybdenum cofactor binding, temperature-dependent effect 1.7.2.3 additional information the enzyme performs trimethylamine oxide reduction during aerobiosis, in the absence of oxygen, Escherichia coli can use alternative exogenous electron acceptors, including trimethylamine oxide, to generate energy, regulation, overview 1.7.2.3 trimethylamine N-oxide + (ferrocytochrome c)-subunit + H+ - 1.7.2.3 trimethylamine N-oxide + (ferrocytochrome c)-subunit + H+ reaction mechanism 1.7.2.3 trimethylamine N-oxide + (ferrocytochrome c)-subunit + H+ trimethylamine N-oxide reductase and dimethyl sulfoxide reductase are identical enzymes 1.7.2.3 trimethylamine N-oxide + (ferrocytochrome c)-subunit + H+ reduction of trimethylamine N-oxide is catalyzed by at least 2 enzymes: trimethylamine N-oxide reductase and dimethyl sulfoxide reductase 1.7.2.3 trimethylamine N-oxide + 2 (ferrocytochrome c)-subunit + 2 H+ - 1.7.2.3 trimethylamine N-oxide + NADH enzyme is highly specific for trimethylamine oxide as alternative terminal electron acceptor 1.7.2.3 trimethylamine-N-oxide + electron donor - 1.7.2.3 trimethylamine-N-oxide + electron donor anaerobic respiration 1.7.2.3 trimethylamine-N-oxide + electron donor trimethylamine N-oxide acts as a terminal electron acceptor for an anaerobic respiratory chain which requires, in addition to a primary dehydrogenase, cytochromes and quinones 1.7.2.3 trimethylamine-N-oxide + electron donor cytochrome 554,557 may be the physiological electron donor 1.7.2.3 trimethylamine-N-oxide + electron donor cytochrome c-556 may be the physiological electron donor 1.7.2.3 trimethylamine-N-oxide + enzyme-MoIV anaerobic respiration